In my adolescence, I suffered from all kinds of addictions. When I finally decided to get help, the counsellor interviewing me asked me what I wanted to get from the experience.

"I want to go back to being my old self," I told her, buoyed by the certainty of youth and what was almost certainly a lot of class A drugs.

"The 'old you' took drugs," she replied without missing a beat, giving me my first inkling that recovery wasn't going to be all tea and sympathy.

We humans love to have a fixed idea about who we are. I'm a father. I'm a CEO. I'm a loudmouth. I'm a depressive. I'm spiritual. I'm an anarchist. It's as if we aren't happy-and I use that word flippantly- unless we have a peg on which to hang the very hats of our existence. And once we've found that peg, we don't really like to move away from it, even when it causes us pain. That day in the therapists office I had created a fictitious former 'me', as though there had only ever been two versions of Liz; the one that took drugs, and the happy and carefree version that came before. And the counsellor was right; she never really existed.

You see these identity fixations all the time. I recently met up with an acquaintance for lunch who managed to hurt my feelings a couple of times over the course of the meal. When I challenged him, he laughed and said "you know me! I don't have a filter!" As if this 'filter' he was talking about was something you were either born with or not, like an appendix or a Psoas minor muscle. He seemed proud of his filterless identity, as if it was something tangible that he could hang on to.

It's not surprising that we do this. At the end of the day, we're all trying to solve the great mystery of existence in our own ways. Indeed, svadhyaya, or self-study, is a cornerstone of the yogic life. So we're on the right track, and it's only natural that labels are appealing-even negative ones- if they help us to fit together a piece of the puzzle.

The issue, however, is one of attachment (they don't lie, those zen masters!). The reality is that we are never exactly the same person even from one day to the next; we're a swirling mass of dying and regenerating cells that are affected by everything from the weather to what we ate for dinner last night. Of course we're still the same in essence, but there are so many things that we say, think and do on autopilot that if we just took a step back, we'd probably realise that that's not really what we feel anymore, or who we are. Even serious mental illness is now being reviewed, with researchers questioning whether it's chronic, life-long and only possible to manage through medication after all.

For many years, I clung to the identity of recovering addict. I felt that it sufficiently explained my entire existence and gave me a role to fulfil. "I'm such an addict!"I would exclaim in situations ranging from waking up grumpy to knocking something over by accident. A few years after starting a yoga practice, I had a revelation: I wasn't the permanently fragile, damaged and sick person that I had been led to believe I was, albeit with good intentions. I was someone who had made some bad choices in my youth, when I didn't know any better. That moment marked a giant shift in my way of thinking about myself and about life.

Even as a yoga teacher I find myself resisting the urge sometimes to be a 'yoga teacher'. I worry that my sense of humour is too naughty, that I am too negative sometimes or quick to judge. That perhaps I should wear more hemp and draw more hearts on things and talk more about vibrations. It can make for some uncomfortable thoughts, but at the end of the day, I can only feel how I feel. I'm a work in progress, after all.

My all-time favourite yoga saying is 'never try to have yesterday's practice'. It's on the mat that we can really see this idea take effect. We bring so many of our own 'mantras' into class with us. I'm too stiff, we might think. I know for a fact I can't do that pose. And of course, body awareness is important, but without the spirit of curiosity, we will never move beyond those fixed ideas. And in life, without the spirit of curiosity and the willingness to be in the moment, we may never see ourselves, see others, as we really are, and not who we think we are.